Functional responses of wild brown trout (Salmo trutta) to drifting brine shrimp (Artemia salina) were studied in a laboratory stream. The general form of the response was Type II, although considerable individual variation was detected in parameters related to attack rate and handling time. The disc equation (Holling 1959) accounted for up to 76% of the variation in prey consumption. Threshold rates of prey capture or drift density seemed to characterize some individuals, but general value could not be specified. Maximum predation rates of 10.8 prey min−1were sustained during feeding bouts of 30 min; short-term peaks of 18 prey min−1were recorded. Analyses of functional responses show promise in future studies of stream communities, particularly with regard to epibenthic foraging.